WATSON, MINN. -- With a bowl full of stars heralding a warm May day to come, the hush on Chippewa Prairie is broken only by the occasional squawk of distant pheasants.

But a few minutes past 5 a.m., a dozen shadowy shapes appear on an acre of grass, and the cacophony begins -- male greater prairie chickens cackling, shrieking and humming in a springtime ritual as old as the prairie itself.

For the chickens, a species rare enough to be of "special concern" in Minnesota, this urgent clamor means they're hopeful they'll find the perfect mate. But for wildlife manager Dave Trauba, watching the "booming" in a nearby blind, it's the worrisome sound of decline.

Helped by two decades of government conservation payments, Minnesota now has more than 3.5 million acres of grassland -- a fragile revival of the vanished landscape the prairie chicken calls home. But record-high crop prices have led landowners to cultivate land they have set aside for a generation.

Once again, the prairie is falling to the plow. And prairie advocates fear a farming frenzy will lay waste to years of effort to restore populations of unique plants and animals, exemplified by the colorful and noisy prairie chicken.

"There's a lot of pressure on the prairie. Right now I'm very pessimistic," said Trauba, manager of the DNR's Lac qui Parle Wildlife Management Area.

"The birds are emblematic of the prairie. And it's not just about prairie chickens. If you want to hear meadowlarks singing or marbled godwits or upland sandpipers, or harriers, you need to have grasslands. If you want to have pheasants, you need to have grass. If you want to have ducks, you need to have grass."

"And so we need to make a way to recognize grasslands for what they are: They're really our heritage here in western Minnesota."

Trauba has been coordinating a 10-year effort to restore prairie chickens to a six-county area in western Minnesota. But in the two years since the birds were left on their own to increase without new imports, the small population is slipping, from 198 in 2006 to maybe 140 this year.

Pheasants are partly to blame, because they can disrupt prairie chickens' nesting routines. Most experts say more types of grassland will allow both birds to thrive. But while the government continues to spend money to acquire and restore prairie -- $4 million for prairie restoration was included in the Legislature's 2008 bonding bill -- it can't keep up with the conversion of grassland into farm fields.

That was then

When settlers got off the riverboats and trains and started marching west, what they mostly saw was grass -- a rolling sea of it, much of it as tall as a horse and rider, covering one-third of what is now Minnesota. Probably it was larger than they could comprehend -- the largest ecosystem in North America, stretching from Canada into Texas and all the way west to the Rocky Mountains, home to herds of bison, elk and antelope, pelicans and whippoorwills, blue-winged teal, sandhill cranes and prairie grouse.

The fertile landscape was obviously good for growing things -- so good that today only about eight-tenths of 1 percent of Minnesota's original prairie remains intact, much of it small islands of bluestem and prairie cordgrass in an ocean of corn, soybeans, sugar beets and wheat.

While the global benefits of Midwest agriculture have been many, prairie advocates point out that it was the native plants that created, protected and nourished the soil itself. They stored and filtered water. The prairie housed and fed an array of plants, insects and animals, some of which, like the greater prairie chicken, are now on endangered or special concern lists. Yet the prairie itself, unlike wetlands, is a landscape without any legal protection.

Grasslands today remain attractive to hunters and birdwatchers. With purple coneflower and other plants yielding ingredients for medicine, they've caught the eye of the pharmaceutical industry, added Brian Winter, director of the northern tallgrass prairie ecoregion for the Nature Conservancy. The prairie is also now being seen as a possible source of alternative fuels as well as a storehouse of carbon dioxide, a key cause of global warming when released into the atmosphere.

"Keeping it there for our ability to learn from it is pretty important," Winter said.

For wildlife, virgin remnants aren't the only prize on the former prairie. Two decades of land-idling payments under the federal Conservation Reserve Program have allowed grass to cover more than 6.6 percent of the Minnesota "farm zone," according to Bill Penning, farmland wildlife program leader for the Minnesota DNR.

The CRP was designed to cushion farmers two decades ago against low crop prices, as well as to manage land for wildlife habitat and soil and water protection. Minnesota landowners put about 300,000 acres into the program the first year, 1985; last year nearly 1.8 million acres were in reserve, the most ever. The CRP is widely regarded as the nation's most significant conservation program.

This is now

But the original motivation for CRP has been turned on its head. Rents offered by the government are in some cases a small fraction of what landowners could receive for putting their land back in play in the new farm economy. In Minnesota, 62,000 acres was taken out of the program between September and April; another 100,000 acres of CRP land is set to expire this year, although many farmers are expected to renew their agreements.

Doug Peterson, president of the Minnesota Farmers Union, has two pieces of CRP land among the 300 acres he farms in Lac qui Parle County, about 30 miles from Chippewa Prairie. He gets $75 to $98 per acre in CRP payments, but these days he could rent the same land for $150 per acre to someone who would farm it.

"If I can double my money, sometimes that's the tale of the tape," Peterson said. "If you want us to be green, no problem. But having put me into this global market, you have to be competitive. The government isn't competitive."

Booming and bust

Out on the margins are prairie chickens. When pioneers first started plowing the prairie and raising crops, the prairie chicken population exploded, sustained by a new and easy source of food. In 1923, Minnesota hunters shot 300,000. But a shift from smaller farms with patches of grazing land to larger farms with row crops devastated the population. Hunting was canceled in 1942 for what turned out to be 60 years.

Minnesota does have a small permanent population of about 7,000, mostly in a thin north-south strip on the edge of the Red River Valley, where the land is too gravelly and poorly drained to farm. That community has been stable enough that limited hunting resumed in 2003, in part to help revive interest in the bird. Last October, 150 hunters shot 122 prairie chickens in a four-day season.

But to the south, where Trauba is working to expand the population, a thriving population of pheasants has been at least as threatening as the plow. Pheasants -- actually an import from China -- often lay eggs in prairie chicken nests, where the prairie chicken hens often hatch the pheasant eggs and then abandon their own. In a 2003 report, John Toepfer, director of research for the Wisconsin-based Society of Tympanuchus Cupido Pinnatus (aka the greater prairie chicken), said that favoritism for pheasants could push the prairie chicken, once the most popular game bird on the Great Plains, toward endangered status.

"We're trying to find out how to have both of them," he said.

Making connections

At the Nature Conservancy's 1,100-acre Chippewa Prairie, the booming ground is a short walk from the end of a winding, grassy driving lane. It's remote enough that in the course of nearly two hours, the antic humming is interrupted only twice by the sound of a passing vehicle. Yet sunrise reveals a working farm less than half a mile away.

"They're not a wilderness bird," Trauba said.

The Nature Conservancy's Winter, who is also president of the Minnesota Prairie Chicken Society, said that what ought to work for prairie chickens in the long term is a patchwork of grassland and agricultural land.

That would allow the birds to connect with one another -- the same principle that drives projects to preserve and restore the prairie itself.

Winter acknowledged that adding or even protecting grassland may be a tall order in the current economy. But it's all part of a larger equation.

"As long as the prairie chicken is still there, the system as a whole, fragmented and beat up as it is, is still doing all right," he said.